tub.dok Sammlung: Open Access Repository der TUHHhttps://tubdok.tub.tuhh.de/handle/11420/2
Open Access Repository der TUHHMon, 21 Jan 2019 19:38:43 GMT2019-01-21T19:38:43ZThroughput time characteristics of rush orders and their impact on standard ordershttps://tubdok.tub.tuhh.de/handle/11420/1985
Titel: Throughput time characteristics of rush orders and their impact on standard orders
Autor/Autorin: Trzyna, Daniel; Kuyumcu, Arif; Lödding, Hermann
Zusammenfassung: The focus of this paper is to present modeling approaches for the rush and standard orders' throughput times. An additional aim is the modeling of a critical rush order share. Starting with a literature review on rush orders, we present an overview of the existing literature which deals with the production planning and control (PPC) and the modeling of the logistic targets of rush orders. Then we present a modeling approach for rush and standard orders' production throughput times. The last section of this paper deals with the problem of the modeling of a critical rush order share.Mon, 21 Jan 2019 14:31:33 GMThttps://tubdok.tub.tuhh.de/handle/11420/19852019-01-21T14:31:33ZDioxin in the Elbe river basin: policy and science under the water framework directive 2000–2015 and toward 2021https://tubdok.tub.tuhh.de/handle/11420/1984
Titel: Dioxin in the Elbe river basin: policy and science under the water framework directive 2000–2015 and toward 2021
Autor/Autorin: Förstner, Ulrich; Hollert, Henner; Brinkmann, Markus; Eichbaum, Kathrin; Weber, Roland; Salomons, Wim
Zusammenfassung: A critical review of the last 25 years of dioxin policy in the Elbe river catchment is presented along seven main theses of the River Basin Community (RBC)-Elbe background document “Pollutants” for the Management Plan 2016–2021. In this period, polychlorinated dibenzodioxins/-furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) will play a major role: (i) as new priority substances for which environmental quality standards (EQSs) need to be derived (Directive 2013/39/EC); (ii) in the search for innovative solutions in sediment remediation (i.e., respecting the influence of mechanical processes; Flood Risk Directive 2007/60/EC); and (iii) as indicators at the land–sea interface (Marine Strategy Framework Directive 2008/56/EC). In the Elbe river catchment, aspects of policy and science are closely connected, which became particularly obvious in a classic example of dioxin hot spot contamination, the case of the Spittelwasser creek. Here, the “source-first principle” of the first cycle of the European Water Framework Directive (WFD) had to be confirmed in a controversy on the dioxin hot spots with Saxony-Anhalt’s Agency for Contaminated Sites (LAF). At the Spittelwasser site, the move from “inside the creek” to “along the river banks” goes parallel to a general paradigm shift in retrospective risk assessment frameworks and remediation techniques for organic chemicals (Ortega-Calvo et al. 2015). With respect to dioxin, large-scale stabilization applying activated carbon additions is particularly promising. Another important aspect is the assessment of the ecotoxicology of dioxins and dl- PCBs in context of sediment mobility and flood risk assessment, which has been studied in the project framework FloodSearch. Currently, the quality goals of the WFD to reach a “good chemical status” are not met in many catchment areas because substances such as mercury do and others probably will (PCDD/Fs and dl-PCB) exceed biota-EQS values catchment area-wide. So far, relating biota-EQS values to sediment-EQSs is not possible. To overcome these limitations, the DioRAMA project was initiated, which has led to improved approaches for the assessment of dioxin-contaminated sediment using in vitro bioassays and to a robust dataset on the interrelation between dioxins and dioxin-like compounds in sediments and biota.Mon, 21 Jan 2019 13:51:56 GMThttps://tubdok.tub.tuhh.de/handle/11420/19842019-01-21T13:51:56ZContributions to topology optimization in flexible multibody dynamicshttps://tubdok.tub.tuhh.de/handle/11420/1979
Titel: Contributions to topology optimization in flexible multibody dynamics
Autor/Autorin: Moghadasi, Ali
Zusammenfassung: This work contributes to the development of the topology optimization of flexible multibody systems. The conventional coupling strategies of the topology optimization and the flexible multibody systems exhibit two limitations regarding its applicability in real-life and industrial application: the high computational cost that limits the optimization size, and the restricted capability of considering nonlinear effects such as contact in flexible structures. These limitations are both addressed in this work, and steps toward the modelling of nonlinearities and the large-scale topology optimization of flexible multibody systems are introduced.; Diese Arbeit leistet einen Beitrag zur Entwicklung von Topologieoptimierungsverfahren von flexiblen Mehrkörpersystemen. Die bisher verwendeten Kopplungen der Topologieoptimierung und der Mehrkörpersysteme weisen zwei Einschränkungen hinsichtlich ihrer Einsetzbarkeit in realen und industriellen Anwendungen auf: den hohen Rechenaufwand und die nur eingeschränkt mögliche Modellierung von nichtlineare Effekte wie beispielsweise den Kontakt von flexiblen Körpern. Diese Einschränkungen werden in dieser Arbeit behandelt und es werden Ansätze vorgestellt, die sowohl die Berücksichtigung von Kontakt als auch die hochdimensionale Topologieoptimierung von flexiblen Mehrkörpersystemen ermöglichen.Mon, 21 Jan 2019 13:39:10 GMThttps://tubdok.tub.tuhh.de/handle/11420/19792019-01-21T13:39:10ZCorrosion of pipeline and compressor materials due to impurities in separated CO2 from fossil-fuelled power plantshttps://tubdok.tub.tuhh.de/handle/11420/1983
Titel: Corrosion of pipeline and compressor materials due to impurities in separated CO2 from fossil-fuelled power plants
Autor/Autorin: Paschke, Benedikt; Kather, Alfons
Zusammenfassung: It is well known that transporting CO2via pipelines even in the supercritical state is not a problem from the corrosion point of view, as long as CO2is almost pure and dry. Depending on the CO2separation technology, however, the untreated CO2stream contains also various impurities such as oxygen, sulphur oxides, nitrogen oxides, carbon monoxide and water. These impurities can cause severe corrosion to pipeline and compressor materials. To avoid corrosion in existing pipeline systems the transported CO2is usually purified and dried, which causes high energetic and financial expenditures. The aim of this investigation is to identify the corrosion potential of impure CO2on pipeline and compressor materials as well as to determine the required purity minimum of the CO2stream from the power plant, from the corrosion point of view. This is done by performing experiments with different materials exposed to impure CO2. It is shown that some impurities enhance the corrosion and with a combination of oxygen, water and nitrogen oxide significant corrosion rates occur.Mon, 21 Jan 2019 12:43:21 GMThttps://tubdok.tub.tuhh.de/handle/11420/19832019-01-21T12:43:21Z